How do I vectorize this?

I'm not sure how to even ask this question without code... I am trying to create a 2d matrix of sums from grouping variables--I tried splitapply but that didnt seem to get me exactly what I want, which is a way to do what I show below:

n = 100;
X = randsample(1:9, n, true);
Y = randsample(15:20, n,  true);
Z = rand(n, 1);

[ji, ~, jL] = grp2idx(X);
[di, ~, dL] = grp2idx(Y);

nJ = numel(jL);
nD = numel(dL);

Ts = zeros(nJ, nD);

for i=1:nJ
    for j=1:nD
        Ts(i,j) = sum(Z(ji==i&di==j));
    end
end

[Walter Roberson]

accumarray looks appropriate

[Walter]

yup! That's it! thank you!